1.2 参与该技术评估和文件编制的资源人员和机构的联系方式

有助于对技术进行记录/评估的机构名称（如相关）

Society for Community Development in Cambodia (SOFDEC) - 柬埔寨

有助于对技术进行记录/评估的机构名称（如相关）

Local Agricultural Research and Extension Centre (LAREC) - 柬埔寨

1.3 关于使用通过WOCAT记录的数据的条件

（现场）数据是什么时候汇编的？:

14/08/2014

编制者和关键资源人员接受有关使用通过WOCAT记录数据的条件。:

是

1.4 所述技术的可持续性声明

这里所描述的技术在土地退化方面是否存在问题，导致无法被认为是一种可持续的土地管理技术？:

否

2.1 技术简介

技术定义:

Rice husks as well as empty seeds are pyrolised and used as a soil amendment in the rice seed beds and the vegetable gardens.

2.2 技术的详细说明

说明:

Biochar is the residue left after the pyrolysis of any organic matter and is used as a soil amendment. Pyrolysis occurs when the organic matter is heated in anaerobic conditions, which is usually done in specially designed kilns. Sometimes it is also made in a conventional fire, which is extinguished before the char turns to ash. Agricultural wastes like rice husks or unfilled grains are mainly used. Biochar can have many positive effects on the soil and plants:
-It buffers the pH, and has usually a high pH due to theash content.
-Due to its porous structure, it holds water and serves as refuge for microorganisms.
-It absorbs and adsorbs nutrients, both cations and anions. They are available for the plant roots.
-It can increase the resistance of plants to diseases.
Due to all these effects, the increased yields are higher than those that can be achieved only through the nutrients contained in the Biochar itself. Biochar is and was used in many parts of the world as soil amendment, with some benefits persisting for centuries. In Cambodia it was used during the Pol Pot regime to reduce the smell of the human faeces that were used on the fields due to a lack of other fertilizers. Today research in the Biochar domain is increasing, especially since the discovery of the man-made terra preta soils in South America.

Biochar is mainly used to increase the fertility, water holding capacity and carbon content of the soil. The fact that the benefits of Biochar addition to the soil remain for several years, unlike chemical fertilizers, makes it attractive to farmers. Other purposes, like the increased resistance of plants to diseases and buffering of nutrients are also of importance.

Biochar was introduced or reintroduced trough different NGOs, JICA (Japanese International Cooperation Agency) in this case study. Because of knowledge exchange between farmers, a rice husk char/ash mix, as residue from the pottery baking, was used already in 2011. In 2013 JICA borrowed a Biochar kiln to the local farmer self-help group with a training, so they could produce Biochar by themselves. The inner part of the kiln (cf. technical drawing) is filled with wood and lit. It is then put into an empty oil barrel, which is filled with rice husks. The heat pyrolyses the husks from the bottom to the top of the barrel, and the gases are burned in the inner part of the kiln and the chimney. Just before the upper part is pyrolysed, the husks are extinguished. There is a weight loss of about 50 to 60 % caused by this process. The Biochar is added to the fields after ploughing, and the fields are harrowed. In this case study, Biochar is used both in rice seed beds and in a vegetable patch. Concentrations of 0.5 kg/m2 are used in the rice seed bed, and 2.5 kg for the vegetables. Due to the little available quantities of husks, Biochar is not applied to the field yet. The use of Biochar is spreading quickly from farm to farm

The analysed area is flat (slope < 2%), with a tropical climate (dry season from November to May and wet season from June to October), and the soils are mostly sandy or loamy. The soil has a low fertility, contains little organic matter, and acidifies. The area has been deforested a long time ago, and the groundwater table is rather high (1-2 m during the dry season, on the surface during wet season).
Due to climate change, farmers notice more erratic rainfall, temperature rises and more recurrent droughts. Rice is the predominant crop grown in the area, since it serves as staple food (mix subsistence and commercial activities). Cattle are usually grazing on the fields after the harvest, without much control. Thus the cattle grazes too often and too much on the same spot, leading to degradation.
The increasing migration rate (the young generation leaves the villages to work in the cities, garment industry or abroad) results in a decrease of available labour force in the area which has detrimental effects on the agricultural activities. Furthermore, the civil war in the 1970s (Khmer Rouge) led to the loss of agricultural knowledge. Several NGOs are trying to re-establish the knowledge.

2.3 技术照片

2.5 已应用该技术的、本评估所涵盖的国家/地区/地点

2.6 实施日期

如果不知道确切的年份，请说明大概的日期:

• 不到10年前（最近）

2.7 技术介绍

详细说明该技术是如何引入的:

• 通过项目/外部干预

注释（项目类型等）:

It was introduced in 2010 by JICA, the Japanese International Cooperation Agency.

3.1 该技术的主要目的

• 改良生产

3.2 应用该技术的当前土地利用类型

注释:

Major land use problems (compiler’s opinion): Soil fertility decline, water availability
Major land use problems (land users’ perception): Water availability. Interestingly the farmer says that soil fertility is not a problem, as the farmers know about the use of compost. The compost application is the problem.

3.3 有关土地利用的更多信息

该技术所应用土地的供水:

• 混合雨水灌溉

每年的生长季节数:

• 1

具体说明:

Longest growing period in days: 210, Longest growing period from month to month: June-December

3.4 该技术所属的SLM组

• 土壤肥力综合管理

3.5 技术传播

具体说明该技术的分布:

• 均匀地分布在一个区域

如果该技术均匀地分布在一个区域上，请注明覆盖的大致区域。:

• 0.1-1 平方千米

注释:

Area unknown and rapidly spreading.

3.6 包含该技术的可持续土地管理措施

3.7 该技术强调的主要土地退化类型

注释:

Main causes of degradation: soil management (Ploughing and bare soil during dry season.), labour availability (Farmers go to work in the garment industry, in construction, or sell their labor elsewhere.)
Secondary causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (Deforestation happened many years ago.), overgrazing (Uncontrolled grazing during dry season.), change in temperature (More hot days according to UNDP and farmers.)

3.8 防止、减少或恢复土地退化

具体数量名该技术与土地退化有关的目标:

• 减少土地退化

4.1 该技术的技术图纸

4.2 技术规范/技术图纸说明

Biochar kiln. In the inner part, the combustion chamber, a wooden fire is lit. The burning chamber is then placed in the oil barrel, which is filled with rice husks. The heat pyrolyses the husks, the gas burn in the chamber and chimney. When pyrolysis is almost completed, the char is extinguished.
Kampong Chhnang
Date: 2014

Technical knowledge required for field staff / advisors: high
Technical knowledge required for land users: moderate (When farmers only buy Biochar the required technical knowledge is low.)
Main technical functions: increase in organic matter, increase in nutrient availability (supply, recycling,…)
Secondary technical functions: improvement of surface structure (crusting, sealing), improvement of topsoil structure (compaction)

Manure / compost / residues
Material/ species: Rice husk Biochar (together with compost, which he already did before)
Quantity/ density: 0.5-2.5
Remarks: Entity: kg/m^2. Distributing on fields and harrowing.

4.3 有关投入和成本计算的一般信息

其它/国家货币（具体说明）:

Riels

注明美元与当地货币的汇率(如相关):1美元=:

4000.0

4.4 技术建立活动

	活动	措施类型	时间
1.	biochar kiln

4.5 技术建立所需要的费用和投入

	对投入进行具体说明	单位	数量	单位成本	每项投入的总成本	土地使用者承担的成本%
设备	kiln		1.0	50.0	50.0
技术建立所需总成本					50.0

4.6 维护/经常性活动

	活动	措施类型	时间/频率
1.	Biochar making	农业学的	Whenever there is time
2.	Adding Biochar to the fields after the compost was plowed in, and harrowing.	农业学的	Yearly, before planting.

4.7 维护/经常性活动所需要的费用和投入（每年）

	对投入进行具体说明	单位	数量	单位成本	每项投入的总成本	土地使用者承担的成本%
劳动力	labour		1.0	20.0	20.0	100.0
设备	machine use		1.0	0.25	0.25	100.0
植物材料	rise husks		1.0	4.0	4.0	100.0
技术维护所需总成本					24.25

注释:

The costs are indicated per unit; a unit is one biochar kiln used on 1 a. The costs were calculated in 2014 for the vegetable beds, where the farmer uses around 2.5 kg/m2. He also uses Biochar on the rice seedling bed, with concentrations of around 0.5 kg/m2, 5 times less than in the vegetable patch. In the vegetable patch the farmer plants cucumber, pumpkin, onion, watermelon and leaf vegetables in the early wet season, before planting rice.

4.8 影响成本的最重要因素

描述影响成本的最决定性因素:

The factors affecting the cost the most are the biochar kiln, and the amount of added Biochar.

5.1 气候

5.2 地形

5.3 土壤

5.4 水资源可用性和质量

5.5 生物多样性

5.6 应用该技术的土地使用者的特征

说明土地使用者的其他有关特征:

Land users applying the Technology are mainly common / average land users
Population density: 10-50 persons/km2
Annual population growth: 0.5% - 1%
Off-farm income specification: handicraft, remittances and factory work

5.7 应用该技术的土地使用者拥有或租用的平均土地面积

5.8 土地所有权、土地使用权和水使用权

土地所有权:

• 社区/村庄
• 个人，未命名

土地使用权:

• 社区（有组织）
• 个人

用水权:

• 自由进入（无组织）

注释:

Land users have a title that is not recognized by the state.

5.9 进入服务和基础设施的通道

6.1 该技术的现场影响

社会经济效应

生产

收入和成本

社会文化影响

生态影响

土壤

生物多样性:植被、动物

6.3 技术对渐变气候以及与气候相关的极端情况/灾害的暴露和敏感性（土地使用者认为的极端情况/灾害）

渐变气候

渐变气候

	季节	气候变化/极端天气的类型	该技术是如何应对的？
年温度		增加	好

气候有关的极端情况（灾害）

气象灾害

	该技术是如何应对的？
局地暴雨	未知
局地风暴	未知

气候灾害

	该技术是如何应对的？
干旱	好

水文灾害

	该技术是如何应对的？
比较和缓的（河道）洪水	不好

其他气候相关的后果

其他气候相关的后果

	该技术是如何应对的？
缩短生长期	好

6.4 成本效益分析

技术收益与技术建立成本相比如何（从土地使用者的角度看）？

技术收益与技术维护成本/经常性成本相比如何（从土地使用者的角度看）？

注释:

The costs for the pyrolysis kiln were not borne by the land user. But as the farmer of this case study wants to build an own kiln as soon as the NGO needs it again, it is positive.

6.5 技术采用

注释:

100% of land user families have adopted the Technology with external material support
100 land user families have adopted the Technology with external material support
Considering only the farmers applying the technology with this stove. Other farmers buy Biochar, or burn the rice husks and extinguish them. But those farmers are nearly impossible to quantify as it changes quickly. The support was the kiln, which is only a small part of the costs.
Considering only the farmers applying the technology with this stove. Other farmers buy Biochar, or burn the rice husks and extinguish them. But those farmers are nearly impossible to quantify as it changes quickly.
In another area of Cambodia where the Ministry of Agriculture, Forestry and Fisheries (MAFF) is doing Biochar research, there was such a strong adoption of Biochar use that there are no more control areas. In Kampong Chhnang, the use of Biochar starts to spread now.

6.7 该技术的优点/长处/机会

土地使用者眼中的长处/优势/机会
Less insect damages where Biochar is applied.
Good growth of vegetables, with increased yields especially for onions.
The rice seedlings are stronger, and the roots break less while transplanting, and the plants recover quickly.
The plants survive a short dry spell better.

编制者或其他关键资源人员认为的长处/优势/机会
Soil amendment with long-term effect, as Biochar has a long half-life period.
Buffering and raising of the pH, especially in sandy soils.
Less washing out of nutrients.

6.8 技术的弱点/缺点/风险及其克服方法

土地使用者认为的弱点/缺点/风险	如何克服它们？
Substrate to make Biochar (rice husks) is difficult to find in the area in big amounts, as only small rice mills are working there.	Rice husks are wasted in other places. Networking with other villages. Use other (waste) sources of organic matter like leaves.
Increased workload for the Biochar production (compensated by the increased yields).	Use a bigger kiln to decrease the workload.

编制者或其他关键资源人员认为的弱点/缺点/风险	如何克服它们？
The energy produced during the pyrolysis is wasted.	Use it to power engines or as heating source. This would only be viable on large-scale kilns.

7.1 信息的方法/来源

7.2 参考可用出版物

标题、作者、年份、ISBN:

Ithaka Journal

可以从哪里获得?成本如何?

www.ithaka-institut.org

标题、作者、年份、ISBN:

Biochar foundation

可以从哪里获得?成本如何?

www.britishbiocharfoundation.org